The technical scope of the present invention is that of devices intended to reduce the visible and infrared signatures of military vehicles from their exhaust gases.
The evolution of thermal camera and sensor technology allows hot sources to be detected over very large distances in a land environment. Such sources may be the exhaust and cooling gases from a vehicle engine. To improve stealth with respect to the evolution of infrared sensors, it is thus necessary for the level of energy radiated by the exhaust and cooling flows of military vehicles to be reduced.
Publications already exist that propose devices to evenly dilute the exhaust gases of a military vehicle. This is the case of patent FR-2776705, which describes a device wherein the air is cooled in a cooling zone before being ejected via a shuttered outlet. These devices, however, have a major drawback. Indeed, although the temperature of the gases ejected is greatly reduced, these gases can be spotted because of the shape of their output flow whose trace can be seen in the form of a wreath by infrared vision equipment.
One solution to rapidly dissipate this wreath consists in applying a jet disperser at the exhaust outlet whose blades radially disperse the gaseous flow. However, a major drawback to this type of solution lies in the fact that such a jet disperser constitutes an obstacle to the gaseous flow thereby reducing the performances of the vehicle (in particular during the vehicle's acceleration phases).